For each clutching and declutching action, the SMG control unit requires the exact clutch position. The clutch is operated via the clutch operating cylinder. The displacement is detected without contact via a PLCD sensor (PLCD = Permanent Linear Contactless Displacement).
The PLCD sensor is integrated on the clutch operating cylinder and it passes on the clutch travel.
The sensor contains an electronic evaluation unit and is supplied with negative and positive (5 V) by the SMG control unit. The piston position is sent to the SMG control unit across a signal wire.
A round magnet is secured to the moving piston and it is shifted parallel to two coils located in a separate casing. Depending on the position of the magnet, the properties of the coils change. This is picked up by the electronic evaluation unit and output as a position signal to the SMG control unit.